1. Field of the Invention
The present invention relates to telephone switching systems in general and, more particularly, to telephone systems wherein interconnections between calling and called parties are performed under control of data processing or computer equipment. The present invention is especially useful in conjunction with telephone interconnection systems which are intended for providing the most economical domestic and international telephone service to those who subscribe to the service by providing apparatus and methods in a system organized for quickly and efficiently employing the most advantageous domestic and international tariff rates to user originated traffic.
Tariff rates for originating traffic often vary greatly. There is a need, therefore, to provide a service that will allow callers to take advantage of tariff rate differences to achieve the most economically advantageous cost for their respective domestic and international traffic.
2. Description of the Prior Art
Interexchange carriers (IXCs) are telecommunication carriers that provide what is commonly known as long distance, or interexchange, service between geographical areas called Local Access Transport Areas (LATAs). It is understood LATAs were created by a United States Federal Court in an antitrust case. The court limited local exchange companies (LECs) to providing telephone service only within LATAs (intraLATA service) and expressly forbid LECs to provide service between LATAs (interLATA service). Thus, IXCs receive originating traffic from the LEC in that LATA, carry the traffic to the terminating LATA, and deliver it to the LEC serving the terminating LATA.
A wide variety of sometimes user interactive arrangements for applying data processing equipment or computers to telephone line switching and control have developed. For instance, U.S. Pat. No. 4,071,698 by Barger et al describes an arrangement for demonstrating and then selling products, such as audio recordings, by the use of a telephone system. It employs either a human operator or an automated program as alternative interfaces. Both procedures make use of an audio repeater wherein product demonstrations are stored.
Statistical acquisition and analysis using a telephone system is disclosed in U.S. Pat. No. 4,792,968 by Katz. An example is in the obtaining of medical data from a selected group of people. A voice generator or a human operator prompts the called party to originate data by telephone instrument actuation. Yet another statistical data handling telephone system using audio units for prompting while utilizing multiple processors is shown in U.S. Pat. No. 4,845,739 by Katz.
U.S. Pat. No. 4,930,150 by Katz applies a processor to make available a multiplicity of formats for services such as public polls, lotteries, auctions, promotions, sales operations and games. The telephone terminal of the user operates a switch to select a format with the processor testing to determine whether the request is proper. Katz et al in U.S. Pat. No. 4,932,046 describes use of a database to simulate a call termination signal to prompt the caller to hang up their telephone at the end of a recorded message.
An arrangement for conference call interconnecting a plurality of parties is shown in U.S. Pat. Nos. 4,939,773 and 4,987,590 by Katz. The system bridges all the telephones of an intended group with a voice generator for prompting. Authorization of the participants is verified.
Use of automatic audio response units in combination with telephone switching operations is shown in U.S. Pat. No. 3,482,057 by Abbott et al. A more interactive functioning in conjunction with a telephone call relay system is described in U.S. Pat. No. 4,975,945 by Carbullido. Remote user terminals communicate with an Audio Response Unit (ARU) or an attended terminal to acquire from the originating user certain identification and/or credit card information. A unique call reference number is assigned to the call and stored. If a need to relay the call exists, the caller is bridged to a terminal block for person to person audio communications.
The prior art has also recognized that it is possible to realize cost savings because of the telephone tariff differentials as between various geographic locations. For instance, calls originating from the United States are frequently less expensive than calls originating from another country.
Thus, a system was developed to take advantage of this tariff differential. In the prior art system, an input line is dedicated to a particular user. That is, for each subscribing user there is a unique dedicated input line. When the user calls into the system on that line, typically allowing it to ring only once, the system employs an autodialer configuration to call the user who responds by entering the desired number. The system dials that number on another line and then bridges the user with it upon response by the called party.
The aforementioned system can likewise establish conference call patches, or the like, all at the local call tariff rates. Such a system is described in the Jan. 9, 1992 New York Times article entitled Hot-Wiring Overseas Telephone Calls by Anthony Ramirez. It suffers the disadvantage of requiring input telephone trunks dedicated to specific users with one such trunk for each user. It also is limited in flexibility and adaptability by the autodialer hardware. Thus a need remains for a system that can function with a minimum number of dedicated telephone trunks, but is expandable with ease to accommodate large numbers of subscribers while likewise enjoying the ability to rapidly relocate the entire system to other geographic areas to take advantage of changing tariff structures.